Fairy-tale trespasser (10)
I believe the answer is:
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">fairy-tale trespasser</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this in another clue)</span><br/ ><br/ >This is all the clue.<br/ ></span>
(Other definitions for goldilocks that I've seen before include "Trespasser" , "Fairy tale porridge thief" , "Visitor for three bears" , "Plant" , "fairly shocked girl" .)